This is a curious issue. It could have been the product of a couple of rare things happening at the same time, but since you are the second person to have this issue recently, it is suspicious. Hopefully an admin will be able to investigate this soon. In the meantime, I would try plugging your email into the Lost Password tool and reading the output to see if your account exists. If it doesn't, you can try registering again and hoping it doesn't recur.